| 1 | //===-- Linux implementation of sigaltstack -------------------------------===// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "src/signal/sigaltstack.h" |
| 10 | #include "src/errno/libc_errno.h" |
| 11 | #include "src/signal/linux/signal_utils.h" |
| 12 | |
| 13 | #include "src/__support/common.h" |
| 14 | |
| 15 | #include <signal.h> |
| 16 | #include <sys/syscall.h> |
| 17 | |
| 18 | namespace LIBC_NAMESPACE { |
| 19 | |
| 20 | LLVM_LIBC_FUNCTION(int, sigaltstack, |
| 21 | (const stack_t *__restrict ss, stack_t *__restrict oss)) { |
| 22 | if (ss != nullptr) { |
| 23 | unsigned not_ss_disable = ~unsigned(SS_DISABLE); |
| 24 | if ((unsigned(ss->ss_flags) & not_ss_disable) != 0) { |
| 25 | // Flags cannot have anything other than SS_DISABLE set. |
| 26 | // We do the type-casting to unsigned because the |ss_flags| |
| 27 | // field of stack_t is of type "int". |
| 28 | libc_errno = EINVAL; |
| 29 | return -1; |
| 30 | } |
| 31 | if (ss->ss_size < MINSIGSTKSZ) { |
| 32 | libc_errno = ENOMEM; |
| 33 | return -1; |
| 34 | } |
| 35 | } |
| 36 | |
| 37 | int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sigaltstack, ts: ss, ts: oss); |
| 38 | if (ret < 0) { |
| 39 | libc_errno = -ret; |
| 40 | return -1; |
| 41 | } |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | } // namespace LIBC_NAMESPACE |
| 46 |